Gastrinomas are the most common symptomatic, malignant pancreatic neuroendocrine tumor (pNET) in patients with or without MEN1 and sufficient numbers of these patients have been entered into our protocols to allow systematic assessment. Studies are now underway, evaluating the natural history of these tumors including the definition of factors determining prognosis and cause of death. Our studies have identified a cohort of 25% of patients in whom the gastrinomas have aggressive growth and 25% who have multiple endocrine neoplasia type 1 (MEN1). During this year information from our prospective studies was used to write four guideline and position papers dealing with the diagnosis of these tumors, treatment of advanced disease and pharmacological approach to management. For MEN1/ZES patients a prospective study of causes of death in these patients was published and compared to 1613 patients in the literature. This study for the first time prospectively evaluates the long-term natural history of these patients, identifies prognostic factors and provides data to better manage these patients long-term. In addition four surgical studies were completed including: two collaborative studies with Dr Kebebow (NCI) in MEN1 patients involving analysis of blood groups correlated with the presence of a primary NET and a study of the value of various preoperative localization modalities for parathyroid disease. Two other surgical studies were also published including a study of the effect of surgery in patients with negative preoperative imaging studies, which demonstrated that tumors can be found in all patients, a proportion cured long-term; leading to the recommendation all of these patients should under exploration if no contraindications. A second study demonstrated for the first time that the presence of lymph node metastases only was associated with a poorer prognosis in patients with gastrinomas and that an increasing number of positive lymph nodes had proportional increased prognostic effect. Furthermore, two chapters in the two major gastroenterology textbooks in the US (Yamada-edition #6, Schlessinger/Fordtran Edition #10) on pancreatic endocrine tumors have been submitted for publication and are now being reviewed.